878178A 1 Mercury SHIFT INTERRUPT HARNESS

Table 1
Diagnostic Codes Table    
J1939 Code and Description     Conditions which Generate this Code     System Response    
190-1
Engine Speed : Low - most severe (3)     The engine is in the run mode and the engine speed drops below the 100 rpm.     The code is logged.
The engine is shut down.
This engine event is latched. (1)    
970-31
Engine Auxiliary Engine Shutdown Switch     The auxiliary engine shutdown switch is use to shut down the engine.
The emergency stop switch is use to shut down the engine.
An emergency stop command is received by the engine Electronic Control Module (ECM) over the CAN data link from the control panel.     The code is logged.
The ECM disables injection. The engine is shut down.    
( 1 ) The engine control switch must be cycled to the OFF position prior to restarting the engine.Probable Causes
Diagnostic codes
Engine shutdown using the customer stop switch
Electronic unit injectors
Engine shutdown using the emergency stop switch at the control panel
Faulty circuit for the emergency stop switch or the customer stop switch
Fuel supplyRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 2
Troubleshooting Test Steps     Values     Results    
1. Check for an Activated Shutdown
A. Interview the operator and determine the reason for the shutdown.
   
Operator
   
Result: The shutdown was intentional.
Ensure that the reason for the shutdown has been corrected.
Reset the control system. Resume normal operation.
Result: The stop was accidental.
Reset the control system. Resume normal operation.
Result: The emergency stop shutdown was activated.
Reset the shutdown switch. Confirm that the condition for the emergency stop shutdown has been resolved.
Cycle the keyswitch in order to reset the control system.
Result: The emergency stop shutdown was not activated.
Proceed to Test Step 2.
   
2. Check for Active Codes and Logged Codes
A. Establish communication between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM).
B. Monitor the diagnostic codes on Cat ET. Check for any active or logged codes.
Note: Wait at least 30 seconds in order for diagnostic codes to become active.
   
Codes
   
Result: A code is active or logged.
Troubleshoot any active codes before continuing with this procedure.
Verify that the repair eliminated the problem.
Result: A code is not active or logged.
Proceed to Test Step 3.
   
3. Check the Circuit for the Stop Switches
A. Inspect the wiring between the switches and the connector of the ECM.
B. Look for damage and/or for corrosion. Refer to Troubleshooting, "Switch Circuit - Test".
   
Connectors and Wiring
   
Result: The connectors or wires are OK.
Proceed to Test Step 4.
Result: The connectors or wires are NOT OK.
Repair: Make all necessary repairs.
Verify that the repair eliminated the problem.
   
4. Inspect the Stop Switches
A. Inspect the stop switches for evidence of damage that has been caused by vibration.
B. Disassemble the switches. Inspect the components for looseness, cracks, and abrasion.
   
Switches
   
Result: The switches are OK.
Proceed to Test Step 5.
Result: The switches are NOT OK.
Repair: Make all necessary repairs.
Verify that the repair eliminated the problem.
   
5. Inspect the Fuel System
A. Visually check the fuel level. Do not rely on the fuel gauge only. If the engine has been run out of fuel, air must be purged from the fuel system.
B. Inspect the fuel system. Refer to Systems Operation/Testing and Adjusting, "Fuel System - Inspect" for more information.
C. Check the fuel tank for foreign objects which can block the fuel supply.    
Fuel
   
Result: The fuel system is OK.
Proceed to Test Step 6.
The fuel system is NOT OK.
Repair: Make all necessary repairs.
Verify that the repair eliminated the problem.
   
6. Test the Fuel Injectors
A. Perform the "Injector Solenoid Test" in order to determine if all of the injector solenoids are being energized by the ECM.
B. Perform the "Cylinder Cutout Test" in order to identify any injectors that might be misfiring.
   
Fuel Injectors
   
Result: The tests were successful.
Proceed to Test Step 7.
Result: The tests were not successful.
Remove the suspect injector, and install a new electronic unit injector. Refer to Disassembly and Assembly.
Ensure that the repairs have determined the problem. Refer to Troubleshooting, "Injector Solenoid - Test".
Verify that the repair eliminated the problem.
   
7. Check the Fuel Quality
A. Obtain a fuel analysis.
Cold weather adversely affects the characteristics of the fuel. Refer to Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation.
B. Check the fuel for contamination.
   
Fuel Quality
   
Result: The fuel quality is OK.
Proceed to Test Step 8.
Result: The fuel quality is NOT OK, and/or the fuel is contaminated.
Repair: Drain the fuel, and replace the fuel.
Verify that the problem is resolved.
   
8. Check for a Mechanical Failure
   
Mechanical Failure
   
Result: A mechanical failure has occurred.
Diagnose the problem and then repair the problem.
Verify that the repair eliminated the problem.
   If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).